Hi guys, i had this problem some time ago and i cant still figure what is wrong.
Water in the water reservoir next to radiator boils from time to time. Head and head gasket was already checked and they were ok. But, water pump is losing some water and also, the part where the radiator cap pushes is a little bit rusty, worn. Could these be the problem? Help me here pls guys.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiChanDC2R &raquo;</TD></TR><TR><TD CLASS="quote">Hi guys, i had this problem some time ago and i cant still figure what is wrong.
Water in the water reservoir next to radiator boils from time to time. Head and head gasket was already checked and they were ok. But, water pump is losing some water and also, the part where the radiator cap pushes is a little bit rusty, worn. Could these be the problem? Help me here pls guys.</TD></TR></TABLE>

1. what was done to find out headgasket was o.k.?
2. how many miles on the car? when was the last time you had replaced anything related to cooling system? (if water pump leaks, replace the seal, or water pump + seal while at it might as well replace timing belt)
3. does your car overheat?

 

id say check your thermostat, make sure its opening all the way also need to get that water pumped changed because if water is leaking out there is a good chance air is seeping in that might cause a air lock.

also when did you last have the coolant system flushed?

 

what do you mean by boils? like boils over or there is bubbling water in the reservoir?

did a comp check?
if you have a leak, there's always a chance air could be seeping in as well.